Tapping tool spindle adapted for support in spaced journals



A. R. HAYES TAPPING TOOL SPINDLE ADAPTED FOR SUPPORT IN SPACED JOURNALSOriginal Filed April 2'7, 1959 INVEN TOR AUGUST R. HAYES mm 8 2 t I wk 12 h2 2 ===============a n mm .N w 8. Q 8 8 2 E $5 8 a m- 2 m. 4 mp a aI? Vq Iww om NQ mm E ATTORNEY States This invention relates to a tappingmachine and particularly to a tool mounting assembly for a tap used in atapping machine which taps a plurality of openings in the sameoperation.

This is a continuation of a previously filed application Serial No.808,991 filed April 27, 1959, and now abandoned.

There is always the problem when tapping a plurality of drilled openingsin the same operation of providing snfiicient safety devices in themachine or tool mounting assembly to compensate in one instance for acondition in which an opening was not pre-drilled prior to tapping, andin the second instance for a condition in which the opening has beenpre-drilled to an insutficient depth to accommodate the full tappingcycle. There are, of course, several mounting attachments for mountingtapping tools which compensate to a limited extent for the aboveconditions. However, most of such attachments are quite cumbersome andgenerally include large additional structures for supporting the tappingtools on the basic drilling and tapping machine. As a result, not onlyare such attachments considerably expensive, but they are generally ofsuch large size that the working space in the machine is considerablyreduced.

It is the main object of this invention to provide a self-containedtapping tool mounting assembly of a new and novel nature which may beinserted in the basic drilling and tapping machine and which is providedwith a simple mounting means as well as a simple drive connection to thedriving elements of the machine.

It is a further object of this invention to incorporate in the tappingtool assembly safety features which will prevent injury or breakage inone instance of the tap or other portions of the assembly should the tapbe forced against a surface not pre-drilled, and in a second instance topermit breakage of the tap but not other portions of the assembly shouldthe tap be inserted in a drilled opening of insufiicient depth toaccommodate the tap for the full tapping cycle. Other safety features inthe mounting structure for the assembly are provided should basicmechanism of the machine fail to function properly.

Other objects and advantages of the invention will become apparent tothose skilled in the art as the nature of the invention is betterunderstood from the following disclosure and as shown in theaccompanying-drawings.

FIGURE 1 is a front perspective view of the central Working portion of ahorizontal drilling and tapping machine incorporating the tapping toolassembly of the present invention. Portions of the machine are brokenaway to show internal mechanism.

FIGURE 2 is a horizontal sectional view of one of the tapping toolmounting assemblies and a portion of its supporting structure.

FIGURE 3 is a sectional view taken substantially along the line 3-3 ofFIGURE 2. 7

FIGURE 4 is a sectional view taken substantially along the line 4-4 ofFIGURE 2.

FIGURE 5 is a horizontal sectional view of a portion of the tapping toolassembly showing a diiferent position of the parts.

Referring to FIGURE 1, there is shown a horizontal atet ice

feed drilling and tapping machine composed of a main support or base 10having upwardly facing horizontal guides or ways 11 on which may bemoved a head 12 having drive mechanism, not shown, but contained withinthe main head housing 13 and generally terminating in a plurality ofdrive shafts, one of which is shown at 16-. The head housing 13 has aninwardly facing peripheral flange 14 on which is bolted, as at 17, amain tool support 15 in the present instance of the type referred towithin the industry as a slip spindle plate support.

The head 12 may be moved along the ways 11 toward a work-holding fixture20 in which is clamped the drilled material or part, here shown as anupright plate 27 with drilled openings 22. The exact means or method ofmoving the head 12 toward the fixture 20 as well as the drivingmechanism for operating the drilling and tapping mechanisms areunimportant for purposes of the present invention. Generally, such areof conventional type and are of a type well known within the industry.

Referring again to the head 12, there are therein pro vided a pluralityof tapping tool assemblies, each indicated in its entirety by thereference numeral 25. The number of assemblies used on a machine is, ofcourse, dependent upon the type of work for which they are to be used.In the normal drilling and tapping processes, there are provided severalpieces of material, each to be drilled at specific locations. Followingdrilling, the drill assemblies are replaced in the slip spindle plate orsupport 15 by tapping tool assemblies 25. In this manner alinement ofthe tapping tools with the drilled holes 22 is provided.

Referring to FIGURE 2, the slip spindle plate or support 15 is composedof a pair of upright and spaced apart parallel walls 26, 27 which areformulated into a common flange 28 at their outer edges which liesadjacent the flange 14. The flange 28 is provided with openings 29 whichreceives the aforementioned bolts 17. The walls 26, 27 are provided withaxially alined opening 30, 31 respectively through which the toolassembly 25 may be inserted.

The tapping tool assembly 25 is composed in part of a rigid elongatedcasing or support sleeve 35 having an inner or first end projectingthrough the opening 30, 31

and an outer end projecting outwardly of the support 15 toward thematerial to be tapped. The casing 35 is provided with an integral radialouter collar or abutment 36 having a radial surface abutting against thewall 27. The collar 36 is held against the wall 27 by a clamping bracket37, the latter being adjustably tightened against the radial surface ofthe collar 36 by an adjusting screw 38. The collar 36, when so clamped,prevents both axial and radial movement of the casing 35. A tapped hole39 is in the wall 27 for receiving the screw 33. As will later becomeapparent, the clamping bracket operates as a slip lock generallypreventing axial movement of the casing 35 but permitting rotation ofthe casing upon excessive force or torque being applied to the casing.

An internal journal or bushing 45 is provided on the inner end of thecasing 35 and is held against movement bymeans of a set screw 4-6. Asecond internal journal or bushing 47 is provided in the opposite orouter end of the casing 35 and is held against movement by a set screw48. The journals 45, 47 are terminated inwardly of the respective endsof the casing at radial shoulders 50, 51. A mid-portion of the casing 35is provided with internal guide means or teeth 52 running axially orlengthwise of the casing.

A rotatably driven member or drive shaft 55 is disposed in the inner endof the casing 35 and extends through the walls 26. It has its externalsurface journailed in the bushing 45. The sleeve. 55 extends axiallybeyond the inner end of the casing and has its projecting portionextending into and adapted for connection to a universal or articulatejoint 56, one portion 57 of which is pinned at 58, 59 to the sleevesection 55b and the other portion 60 of which is pinned at 61 to thedrive shaft 16. Often the shaft 16 will be at an angle to axis of theshaft 55, and consequently the articulate connection will permit suchwithout aifecting the drive relation between the two. An end plug 62 isprovided to add strength at end 555 of the sleeve. A thrust washer 63 isdisposed between the end of the casing 35 and the universal jointsection'57. The sleeve 55 is provided with an integral radial collar 55awhich seats behind the shoulder 50 to limit axial movement of thesleeve. The internal surface of the sleeve 55 is splined at 65.

An elongated spindle 70 is disposed within the casing and has an adapterend 71 projecting beyond the outer end of the casing, a portion 72journalled in the journal 47, a splined end 73 carried in the splinedinner surface of the drive sleeve and a threaded mid-portion 74 betweenthe portions 72, 73. The threaded mid-portion 74 is spaced radiallyinwardly of the axial teeth 52. The splined end 65 of the sleeve 55 andthe splined end 73 of the spindle function as connecting means betweenthe sleeve 55 and spindle effective to cause rotation thereof in unison,but permitting relative axial movement between the sleeve 55 and spindle70.

A nut or radial element is positioned in the space between the threadedportion 74 and the teeth 52, the nut 80 being internally threaded at 8 1on its inner axial face to mount on the threaded portion 74. The nut hasexternal axial teeth 82 on its outer axial face which engage the teeth52. As may readily be seen, therefore, the nut is permitted axialmovement but is restricted against angular movement relative to thecasing 35. The nut element has axially spaced radial faces 83, 84. Theface 84 abuts against the shoulder 51 of the journal sleeve 47. Springor biasing means in the form of a collar 85 and compression spring 86extends between the face 83 and the end of the sleeve 55. The spring 86biases the nut against axial movement away from the shoulder 51.

The tool mounting means for a tap 90 is of conventional type. Theadapter end 71 of the spindle 70 is provided with an axial opening inwhich is inserted an adapter 91, the outer end of which is threaded, asat 92, to receive 'an adjusting collar 93. The collar 93 normally abutsthe end of the spindle 70 and provides accurate axial positioning of theadapter 91 relative to the spindle '70. A set screw 94 is provided tolock the adapter '91 in the adapter end 71 of the spindle 70. Containedwithin the adapter 91 is a conventional type pair of tap drivers or jaws95 which snugly engage the shank end of the tap 90. The tang end 96 ofthe driver 95 may be seen through a slot 97 in the end portion '71 ofthe spindle 70. A tool may be inserted through the slot 97 for purposesof engaging the tang end 96 and knocking the drivers 95 and tap 90 outof the adapter 91.

The invention operates in the following manner. Assuming that the workor material 21 has been drilled substantially 'as shown at 22, theentire drill assembly is removed at the location of the universal joint56 by removing a suitable pin in the joint, the exact connecting pinbeing unimportant. However, it should be recognized that it isoftentimes the normal procedure to connect the drill assembly to theshaft at a point behind the wall 26. The drill assembly is slipped outof the slip spindle plate 15 via the openings 30, 31, and the entiretapping tool assembly 25 is inserted through the same openings and isconnected to the drive element or shaft 16 through the universal joint56. Here it should be recognized that the diameter of the drive sleeve55 as well as the sections 57, 60 of the universal joint 56 is such asto permit movement through the openings 30, 31.

In initial operation of the unit. the head 12 is brought 4 to a positionwhereby the taps 90 are proximate the work or material 21 and inalinement with the drilled holes 22. The drive shafts 16 are then drivenand the drive sleeve 55 causes the spindle 7 i to rotate.

The spring 86 is of such 'force to cause the nut element 80 to abutagainst the shoulder 51. Therefore, as the spindle rotates, the spindleis fed axially outwardly by the nut element '80. It should be hereunderstood that the teeth on the tap '96 have the same pitch as thethreaded central portion "74 of the spindle. Consequently, the spindleis fed outwardly at the same rate required by the tapping tool 90.Obviously, of course, once the tapping action has begun the tap 99 willexert force on the spindle to feed at the correct rate.

Should one of the taps 9t) encounter an obstruction which preventstapping, such as would occur should the tapping tool assembly be broughtagainst the material 21 at a point which has not been predrilled, thespindle 70 is fed through the casing 35 on the nut element 89 until thetap 90 contacts the undrilled'material 21. Upon contact with thematerial, further rotation will cause the nut element 80 to be fedaxially inwardly by the threaded portion 74 of the spindle. The spring86 will be compressed and the nut will move to substantially theposition shown in FIGURE 5.

As the respective shaft 16 is reversed in direction of rotation for thenormal purpose of removing the tap from its opening, the spring 86 willcause the nut element to be threaded axially outwardly along thethreaded portion 74 of the spindle 70 and back into an abutting positionwith the shoulder 51 or as shown substantially in FIGURE 2. Therefore,there is built into the present tapping tool assembly 25 a safetyfeature protecting the tap as well as the entire tool assembly frominjury should the tap encounterv an obstruction which prevents a tappingoperation.

In the normal drilling operation there occur instances in which thedrilled openings are not of the proper'depth. As a consequence, the tap9% will begin its tapping operation but will reach the end of theopening prior to the normal completion of the tapping cycle where itwill be held against further rotation. The drive shaft will continue toapply torque to the tap which will cause breakage of the tap. Thespindle '70 and broken portion of the tap will continue to rotate andwill forcethe nut 74 axially inwardly much in the same manner as whenthe tap strikes a surface which is not pre-drilled. As a consequence thetap will be broken, but the more expensive mounting assembly will not beharmed.

The adjustable clamp means 37, 38 operates to prevent injury to themounting assembly 25 clue to malfunction of the assembly or of't'hemachine. For example, should for some reason the nut 74 become locked orfrozen to the spindle and casing and not properly feed out the spindle,then operation of the drive shaft 16 will apply torque to the entireassembly as a unit. Or as a further example, should the drive shaft 16not shut off at the end of a cycle combined with the nut element 80being at its maximum axial position, as shown in FIG- URE 5, then thetorque will again be applied to the unit as a whole. In either example,upon sufficient torque being applied, the clamp means 37, 38 will permitthe casing, to rotate in the openings 30, 31 prior to damage being doneto the tool mounting assembly. Therefore, the present assembly addsfurther protection of a basic safety feature preventing breakage ordamage to the assembly due to improper functioning of the machine orassembly. 7

While only one form of the invention has been shown, it should berecognized that other forms will occur to those skilled in the art. Itshould therefore be understood that the present form was shown anddescribed in detail for the purpose of clearly and conciselyillustrating the principles of the invention, and it is not theintention by so describing it to narrow or limit the invention beyondthe broad concept as set forth in each of the appended claims.

What is claimed is:

1. A tapping tool assembly adapted for mounting in two rigidly joinedand spaced-apart walls disposed between a drive mechanism and materialto be tapped, said walls being characterized by having a pair of alinedopenings, said tapping tool assembly comprising: an.

elongated rigid casing extending through the openings and supported bythe walls and having means thereon for preventing rotational and axialmovement, said casing having an inner end adjacent the drive mechanismand an outer end adjacent the material; a first journal in the casingadjacent the inner end; a drive member projecting into and journaled insaid first journal so as to normally extend through at least one of thewalls when the assembly is mounted thereon, said member having an endoutside of the casing adapted for an articulate connection to the drivemechanism to effect rotation thereof and an end within the casing; meansfixing the drive member against axial movement relative to the casing; asecond journal adjacent the outer end of the casing, an elongatedspindle journaled in said second journal and having an end portionwithin the casing in telescoping and driving relation with the end ofthe drive member for effecting rotation of the member and spindle inunison, said casing and spindle having radially spaced adjacentportions; a radial element having axial surfaces disposed in the spacebetween said adjacent portions, the radial element being threaded on oneof said axial surfaces and having axial guide means on the other of saidaxial surfaces, one of said adjacent portions being threaded toaccommodate the threaded surface of the radial element, the other ofsaid adjacent portions having means accommodating said axial guide meanswhereby said radial element may move axially relative to that adjacentportion; means biasing the radial element axially toward the outer endof the casing; and tool adapting means on the outer end portion of thespindle for attaching a tap thereto.

2. A tool mounting assembly for a tap of a given pitch and adapted forinsertion in a pair of alined openings in a two-wall slip spindle plate,comprising: an elongated rigid casing having an outer peripheral surfaceinsertable axially in the openings with means thereon preventingrotational and axial movement relative to both walls, the casing furtherhaving between the inner and outer ends thereof an internal surface withaxially extending guide means; a rotatable drive member journaled in theinner end of the casing so as to normally extend through at least one ofsaid two walls when the assembly is mounted therein and having an axialopening therein; said member having an end outside of the inner end ofthe casing adapted for articulate connection to a drive element; meansfixing said drive member against axial movement relative to the casing;an elongated spindle journaled in the outer end of the casing and havingone end portion thereof projecting beyond the outer end of the casing,and a threaded portion having a thread pitch of the tap and radiallyspaced from and internally of the axial guide means on the internalsurface of the casing, said spindle further having an inner endinsertable in the axial opening of the drive member for connecting saidspindle to said drive member and efiecting rotation of the member andspindle in unison, but eifective to permit relative axial movementbetween the member and spindle; a nut element internally threaded tomount on the threaded portion of the spindle and having an outer surfaceengageable with said axial guide means whereby said nut element may moveaxially relative to the casing; means biasing the nut element axiallytoward the outer end of the casing; and an adapter on the outer end ofthe spindle connecting the tap to the spindle.

3. The invention defined in claim 1 further characterized by the axialguide means being on the internal surface of the casing and onlypartially through the thickness of the casing wall whereby the radialelement and the adjacent portion of the spindle are completely enclosed.

4. The invention defined in claim 2 in which the drive member andspindle are journaled in the casing by axially spaced journals at itsinner and outer ends respectively so that the spindle is directlyjournaled in the journal adjacent the outer end, and the drive member isdirectly journaled in the journal at the inner end and the axial openingin the drive member accommodates the end of the spindle internally ofthe casing for axial movement while preventing relative radial movementbetween the spindle and drive member whereby the drive member and itsrespective supporting journal at the inner end of the casing willindirectly support said inner end of the spindle.

5. The invention defined in claim 4 further characterized by the journalat the inner end being rigid with the casing and providing a radialshoulder within the casing facing said nut element, and the biasingmeans is in the form of a coil spring surrounding the spindle anddisposed between the element and the respective radial shoulder of theinner journal.

References Cited in the file of this patent UNITED STATES PATENTS

